I finally got pointed in the right direction to find the mouth soaping scene in one of the Headmaster’s Study movies available from Lupus. I blogged about it here and a commenter identified it as being in From The Headmaster’s Study: The Anarchy (that’s a streaming VOD link if the Lupus site doesn’t work for you for whatever reason).

Unlike a traditional mouthsoaping, this one does not involve an actual bar of soap in her mouth. Instead, in a scene lasting just 2-3 minutes, the headmaster carefully wets the soap bar in a basin, uses it to thoroughly lather a wet washcloth, and then holds her nose while he carefully and completely scrubs the inside of her mouth with the soapy cloth.

She’s submissive and uncomplaining throughout, although she does appear close to tears at moments!

Her subdued response to the punishment only serves to highlight her plight. She’s not a bad girl, she’s a good girl trapped in a bad situation. A very bad situation, as her screaming and thrashing under his cane (and birch) illustrates later in the movie…